sanford



R. S. SANFORD BRAKE April 24, 1928. 1,667,395

Filed Nov. 2, 1925 2 Sheets-Sheet 1 INVENTOR RQYY 5. SAN FORD ATTORNEY R. S. SANFORD BRAKE 2 Sheets-Sheet 2 Filed Nov. 2 1925 INVENTOR ROY 5. 5ANFORD BY v ATTORNEY Patented Apr. 24, l928.

,UNiTED STATES rises PATENT ROY S. SANFORD, OF SOUTH IBEND,INDIANA, ASSIGNOR T0 BENDIX BRAKE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

BRAKE.

' Application filed November 2, 1925/ Serial No. 66,272. a

This invention relates to brakes, and'is illustrated as embodied in internal expanding automobile brakes; An object is to arrange the parts of a brake of the type in which a servo shoe forces another shoe against the drum, in such a manner as to secure extreme 1y smooth and. progressive operation, without requiring too great accuracy in manufacture. r

I Iaving this object in view, I prefer to connect the shoes (which in one modification are shown overlapping at theirwends) by a rigid connecting member or link which can float freely to adjust itself to the positions of the shoes. A spring is providedfor urging the connected ends of the shoes away from the drum, to insure engagement with the drum first by the servofishoe, which: then turns with the drum toovercome the spring In the drawings thespring is shown connected tout-he rigid link, holding the shoes against stationary stops, An important minor feature of novelty relates to arranging one stop as a fulcrum about which the servo shoe swings when applied, so that the unconnected end of the shoe first turns with the drum to force the connected end outward, partly overcoming the spring, and the entireservo shoe then turns with the drum' to force theother shoe against the drum, thus securing very smooth and gradual application of the brake. i i

Other features of novelty relate to forming a shoulder on the brake spring,'for a tool taking the tension of the spring while it is being attached or detached and to various other novel and desirable particular constructionswhichwillbe apparent from the following description of the illustrative embodiments shown in theaccompanying drawings, in which: a

Fig. 1 ,is a vertical section through one brake, just inside the wheel, showing the shoesin side elevation; y a

I Fig. 2is a similar section through a secondbrake; p j i Fig. 3 is a section on the line 3-3 of Fig. 2, showing the linkage connecting the shoes;

Fig. 4 is an'elevation of one of the springs, on a larger scale; 4 i

Fig. 5 is a similar view of another of the and apply the other shoe. a

springs;

Fig. 6 is a-seetion through one spring on the line 6 6 of 4:, but showing also a partial side elevation of a tension-taking tool in place; and

Fig. 7 is a, similar view on the line"7 7 of Fig. l

The brake of Fig. 1 includes a drum 1O rotating with the wheel (not 1 shown), and within which aretai'rangcd end to end a-'reverse shoe 12 anchored a't-l l on a backing plate 16, a central shoe 1S anchored on the backing plate at 20, and a servo or unanchored shoe 22. Shoe 12 is forked or otherwise formed at its endto straddle or overlap the end of shoe 1S, anchor 14 passing through a relatively large opening in shoe 18 and anchor 20 passing through a relatively large opening in shoe 12. Thisar'rangement is more fully described in U. S. Patent No. 1,567,716. v

Shoes 18 and 22 are connected by rigid links 241, there being preferably two or them, one on eachfside of'the shoes, and which are pivoted to shoe 18 by a pin 26 and to shoe 22 by a pin 28. Shoes 12 and 22'arc forced apart to apply thebrake by means such as a double cam 30. against the resistance of a return spring 32 connected at its opposite ends to the, two shoes. The connectedends of shoes 18 and 22 are urged: away from the drum by means shown as a spring 34 con; nected at one end to backing plate 16 and'at its other end to fine or bothlinks 24, and holding the shoes in positions determined by eccentric adjustable stops 36 and38.

When the cam 30 or its equivalent is operated to apply the brake, shoe 12 is forced against the drum at once, to retard reverse movement of the car, but shoe 22, being held by spring 34ragainst stop 36, fulcrumsabout the entire servo shoe turns with the drum,

actingthrough links 24- and additionally overcoming spring 3 1, to force shoe 18 against the drum. Itwill be seen that this gives a gradual, smooth, progressive application of the brake. i i p i y Each of the springs 32 and 3 1 is upset near its ends to form spherical bulges or shoulders to be engaged (Fig. 6) by a forked tool 42- which takes the tensionof the spring while it is being attached or detached, thus faciliiii , spread the metal. to form disk-shaped portions serving as shoulders to be engaged by tool 42 (Fig. 7).

Also servo shoe122 is forked or otherwise formed at its ends to straddle or overlap the end oi the anchored shoe 118 (Fig. 3). A single link 1524;, held slidably against the backing plate 16, is pivoted to the end of shoe 122by a pin 126 passing through a relatively large opening in shoe 118, and is piv-' oted to the end of shoe 118 by a pin 128 passing through relatively large openings in the arms forming the forked end of shoe 122.

While two illustrative embodiments have been described in. detail, it is not my intention to limit the scope of the invention to those particular (embodiments, or otherwise than by the terms of the appended claims.

I claim:

1. A brake comprising, in combination, a drum, shoes engageable with the drum and one of which is pivotally anchored and a rigid floating link pivotally connected at its ends directly to the shoes, the shoes being so arranged that the; unanchored shoe turns with the drum and forces the other shoe against the drum through said link.

2. A brake'comprising, in combination, a

drum, shoes arranged end to end and engageable with the drum and one of which is anchored, and a rigid floating link pivotally connected at its ends directly to the shoes, the shoes, being so arranged that the unanehored shoe turns with the drum and forces the other against the drum through. said link.

3. A brake comprising. in combination. a drum, a shoe anchored at one end within the drum, a servo shoe arranged at the. unanchored end ofthe anchored shoe, and a rigid floating link pivoted at its ends to the adjacent ends respectively ofthe two shoes.

4. A brake comprising, in combination,; a drum, a shoe anchored atone end within the drum, a servo shoe arranged at the unanchored end of the'anchored shoe, a rigid floating link pivoted at its ends to the adjacentends respectively of the two shoes, and means for holding the anchored shoe away from the drum until after the servo shoe engages'the drum and turns with the drum to act through said link to force the anchored shoe against the drum.

5. A brake comprising, in combination, a drum, a shoe anchored at one end within the drum, a servo shoe arranged at the unanchored end of the anchored shoe, a rigid floating link pivoted at its ends to the adjacentends respectively of the two shoes, and a spring for holding the anchored shoe away from the drum until after-the servo shoe engages the drum and turns with the drum to act through said link to force the anchored shoe against the drum.

6. A brake comprising, in combination, a drum, a shoe anchored at one end within the drum, a servo shoe arranged at the unan chored end of the anchored shoe, a rigid floating link pivoted at its ends to the adjacent ends respectively of the two shoes, and a spring connected to said link and urging the anchored shoe away from the drum until after the servo shoe engages the drum and turns with the drum to act through said link to force the anchored, shoe against the drum.

7 A brakecomprising, in combination, a drum, a shoe anchored at one end within the drum, a servo shoe arranged at the unanchored end of the anchored shoe, a rigid floating link pivoted at its ends to the adjacent ends respectively of the two shoes, and a brake-applying device acting on the unlinked end of the servo shoe.

8. A brake comprising, in combination, a drum, a shoe anchored at one end within the drum, a servo shoearranged at the unanchored end of the anchored shoe, a rigid floating link pivoted at its ends to the adjaccnt ends respectively of the two shoes, :1. third shoe anchored at the end next the anchored end of the first shoe and arranged with its unanchored end adjacent the unlinked end of the servo shoe, and means for forcing the adjacent ends of the servo shoe and the third shoe apart to apply the brake.

9. A brake comprising, in combination, a drum, a shoe anchored atone end within the drum, a servo shoe arranged at the unanchored end of the anchored shoe, a rigid floating link pivotedatits ends to the adjacent ends respectively of the two shoes, a third shoe anchored at the end next the an-- chored end of the first shoe and arranged with its unanchored end adjacent the 1mlinked end of the servo shoe, and a double cam betweenthe adjacent ends of the servo shoe and the third shoe to force them apart to apply the brake.

10. A brake comprising, in combination. a drum, a shoe anchored'at one end within the drum, a servo shoe arranged at the unanchored end of the anchored shoe, a rigid floating link pivoted at its ends to the adtowardeach other away from the drumand' urging the unanchored end ofthe first shoe away from the drum. i

11. A brake comprising, in combination. a drum, a shoe anchored at one end withintho drum, a servo shoe arranged at the unanchored end of the anchored shoe, a rigid floating link pivoted at its ends to the adjacent ends respectively of the two shoes, at third shoe anchored at the end next the anchored end of the first shoe and arranged with itsunanehored end adjacent the unlinked end of the servo shoe, means for forcing the adjacent ends of the servo shoe and the third shoe apart to apply the brake, a

' spring urging the servo and third shoes totill ward each other away fromthe drum, and an auxiliary spring urging the unanchored end of the first shoe away from the drum.

12. A brake comprising, in combination, a drum, a shoe anchored at one end within the drum, a servo shoe arranged at the unanchored end of the anchored shoe, a rigid floating link pivoted at its ends to the ad jace-nt ends respectively of the two shoes, a third shoe anchored at the end next the anchored end of the first shoe and arranged with its unanchored end adjacent the unlinked end of the servo shoe. means for forcing the adjacent ends of the servo shoe and chored, a link pivotally connecting the overlapping ends of the shoes, and means for forcing one shoe against the drum to turn with the drum and act through said link to force the other shoe against the drum.

let. A brake comprising, in combination, a drum, a pair of overlapping shoes within the drum, a link pivotally connecting the overlapping ends of the shoes, a third shoe overlapping the opposite end of one of said pair of shoes, and means for forcing said third shoe and the other of said pair of shoes apart against the drum to apply the brake.

15. A brake conlprising, in combination, a drum, a pair of overlapping shoes within the drum, a link pivotally connecting the overlapping ends of the shoes, a third shoe overlapping the opposite end of one of said pair of shoes, means for taking braking torque from the overlapping ends of the third shoe and said one shoe, and means for forcing said third shoe and the other of said pair of shoes apart against the drumto apply the brake. 1

16. A brake comprising, in combination, a drum, a pair of shoesarranged end to end within the. drnnna floating link pivot-ally connecting the adjacent ends of said shoes, a separate stop engaging each of said adja cent ends in idle position, and a spring connected to the link and urging the shoes against. said stops. i

chored, a link connecting the adjacent end,

of the shoes, a spring urging the linked ends of said shoes away from the drum, means for forcing thennlinked end of the-unanehored shoe against the drum, and a stop engaging the unanchored shoe and about which the shoe fulcrums when its unlinked end is forced outward so that the linked end at first turns inward, being held by said spring against the stop, the unlinked end then turning with the drum partly to overcomethe spring and force the linked end against the drum, and the entire unanchored shoe then turning with the drum additionally to overcome the spring and act through the link to force the anchored shoe against the drum. v

18. A brake comprising, in combination, a drum. a pair of shoes arranged end to end within the drum and one of which is anchored, means connecting the adjacent ends of the shoes. a spring urging the connected ends of said shoes away from the drum, means for forcing the unconnected end of the unanchored shoe against the drum, and a stop engaging the unanchored' shoe and about which the shoe fulcrums when its unconnected end is forced outward so that the connected end at first turns inward, being held by said spring against the stop, the umamnected end then turning with the drum partly to overcome the spring and force the connected end against the drum, and the entire unanchored shoe then turning with the drum additionally to overcome the spring and act through said connecting means to force the anchored shoe against the drum.

19. A brake comprising, in combination, a drum, a pair of connected shoes anchored within the drum anchored at one end of one of the shoes, means for forcing the opposite end of the other shoe against the drum, a spring urging the connected ends of the shoes away from the drum, and a stop engagin the unanchored shoe some distance from its connected end and against which the shoe is held by said spring.

20. A brake comprising, in combination, a drum, a friction device engage able with the drum, and a spring urging said device away no i from: the drum and formed with a sharp from the drum and upset to form an inteshoulder for engagementby a tooitaking gl'ill projection for engagement by a tool the tension of the spring While it is being taking the tension of the spring While it is attached or detached. 7 being attached or detached.

21. Ahrake comprising, in combination, a In testimony whereof, I have hereunto drunnu friction device engagenbie with the signed my name.

drum, and a spring urging said device away ROY S. SANFORD. 

